1. Field of the Invention
The present invention relates to a water flush toilet bowl in which a bowl main body and a trap device are separately constructed, and a cast molding apparatus for such a toilet bowl.
2. Description of the Related Art
If a water flush toilet bowl is formed by slip casting as a unit including a trap portion thereof the trap portion is exposed at a side face of the toilet bowl. This is not only undesirable from a view point of ornamental design but also has a drawback that it is easily stained and difficult to wash out.
A water flush toilet bowl provided with a skirt portion around the main body of the bowl, in which the trap device is accepted, has already been disclosed, for example in U.S. Pat. No. 4,672,689 or International Publication WO 95/27833. When the skirt portion is provided around the main body of the bowl, since it is difficult to form the main body of the bowl and the trap together as a unit due to restrictions in the construction of the casting mold, the main body of the bowl and the trap must be separately formed, and then the trap is attached to the bowl main body afterwards.
With the toilet bowl shown in International Publication WO 95/27833, only a lower face is opened, and therefore it is difficult work to attach the trap afterwards. On the other hand, with the toilet bowl shown In U.S. Pat. No. 4,672,689, as seen in FIG. 35, it is easy work to attach the trap device 101 afterwards since the lower face and the rear face of the toilet bowl 100 are continuously opened.
However, in the toilet bowl shown in U.S. Pat. No. 4,672,689, it is impossible to adjust the length of the trap device easily with respect to fitting the position of a drain pipe, and therefore cutting the drain pipe is necessary for adjusting the length thereof, which is troublesome.
Further, when the lower face and the rear face of the toilet bowl are continuously opened, the rear edge portion 103 of the skirt portion 102 is short or insufficient in mechanical strength, and therefore cracks and breaks are easily caused at this portion during the process of attaching the trap device. For resolving this problem, the thickness of the skirt portion 102 must be increased, however it takes a long time build up sufficient thickness in the casting process and also production costs are greater.